Evaluation of Impactor’s Collection Efficiency on Airborne Bacteria by Type of Agar Media and Storage Condition

Abstract

The range of reduction rates of airborne bacteria concentration at 6 hrs, 12 hrs, 24 hrs and 48 hrs, which means a storage time until input of agar media into incubator after air sampling with an impactor, were 15-20%, 25-40%, 35-50% and 55-70%, respectively, compared to initial concentration. Types of agar media and storage thermal condition did not significantly affect a collection efficiency of impactor in terms of evaluating airborne bacteria level (p＞0.05). To better improve the impactor’s collection efficiency of airborne bacteria, based on the result of this study, it is recommended that the vicinity of 25℃ should be sustained until input of agar media into incubator after air sampling.